Traditional industrial coatings have for years been based in significant part on backbone resins having active hydrogen groups crosslinked with various derivatives of amino-1,3,5-triazines. Most notable among the amino-1,3,5-triazine derivatives are the aminoplasts such as the alkoxymethyl derivatives of melamine and guanamines which, while providing excellent results in a number of aspects, have the disadvantage of releasing formaldehyde as a volatile by-product under curing conditions and requiring relatively high temperatures to adequately crosslink the film.
Despite the excellent film coating properties, which can be achieved with aminoplast crosslinked systems, the coatings industry is under great pressure to reduce the environmentally undesirable emission of formaldehyde. In addition, high temperature crosslinking systems require more energy to cure and/or crosslink slower resulting in less throughput. As a result, it has long been a desire of industry to find acceptable alternative crosslinkers and coatings systems, which emit no formaldehyde, or low amounts of formaldehyde, are soluble and/or stable in common solvents used in the coating industry and cure at relatively lower temperatures.
U.S. Pat. Nos. 3,806,508 and 4,180,488 disclose the preparation of resins prepared by reacting melamine with a mono(alkylaldehyde) and an alcohol. However, neither patent discloses nor teaches the use of organic acids to stabilize the resin composition.
U.S. Pat. No. 4,454,133 discloses the preparation of antimicrobial compounds prepared by reacting an amide or imide compound with poly(alkylaldehydes), e.g., glutaraldehyde. However, the patent neither discloses nor teaches reacting an amino-based compound with mono(alkylaldehydes) and/or poly(alkylaldehydes) and alcohol to form a crosslinking composition, nor discloses the use of organic acids to stabilize the composition.